On Wed, Mar 30, 2011 at 03:15:59PM -0700, Nick Prince wrote:
> In Russell’s book there is a section on “Arguments against QTI”
> And I want to put forward some issues arising from this.
> It seems that (if MWI is true) we live in world(s) in which we appear
> to live a finite, small lifetime of around 70 years.  From the many
> discussions on this list, it also seems to me that, this is the single
> biggest argument (that I can understand) which points to the QTI being
> false.  Unfortunately it appears that the whole ASSA/RSSA debate -
> which might have been a candidate for clarifying the issue - turns out
> to be a confusing (to me anyway) and polarising approach.
> So is QTI false?
> Russell does put forward a possible solution in his book. He suggests
> the idea that as memory fades with dementia then perhaps the conscious
> mind becomes so similar to that of a newborn - or even unborn - baby
> that perhaps “a diminishing?” consciousness always finds an
> appropriate route (in some branch) to avoid a cul de sac event.
> (This is one possible form of the No Cul De Sac Conjecture =NCDSC)

This is a variant of an argument that David Parfit uses in his book
"Reasons and Persons", where he considers a continuum from his mind
to that of Napoleon. (Don't flame me if I get the details wrong - the
essence is what is important). I hadn't read that book at the time I
wrote mine, otherwise, I would undoubtedly have cited it.

Now in the case of Parfit's argument, I find considerable doubt that
the argument can be made to work. Whilst, if I randomly knocked out 1%
of your neurons, you will still be awake, and probably little
different from the experience, if I knocked out certain "keystone" (as
the concept is called in ecology) neurons to a level of 1% of all
neurons, your brain function would fall apart quite rapidly. Yet to
transition from your brain to that of Napoleons would require rewiring
those same keystone neurons, and that, I believe casts significant
doubt that the continuum is possible, even in principle.

Now, we also know that infant minds are not a tabula rasa. So I am
sceptical that the transition of a dementiaed mind to an infant mind
is possible, for just the same reason.

> To avoid the cul de sac event, there would surely have to be a
> critical  stage whereby  consciousness diminishes and reaches a form
> of cusp at the point of lapsing into non existence and thereby
> requiring the necessity of an extension route or branch to another
> consistent universe.  In short, from the third person POV, the person
> dies but from the first person -(now primitive) consciousness – state,
> there is rebirth.  I am thinking that before we get to the croaking
> Amoeba there is a discontinuity in what we understand as consciousness
> – at least the form that applies to the NCDSC.

The no cul-de-sac conjecture is perhaps a bit of a misnomer. It is not
really well defined enough to embark on a proof, which it really ought
to be. Certainly, in the Theatetical formulation that Bruno is
investigating, there are NCDSC-like theorems in some hypostases, ([]p-><>p
IIRC). Also, in QM, an observation along the lines of something like
m(t)=<\psi(t)|P(o(t))|\psi(t)>, where P is a project operator onto all
worlds consistent with some observer o. The no cul-de-sac conjecture
would correspond to m(t) != 0, except on a set of measure
zero. Assuming m(t) is analytic, this is kind of obvious, but
unfortunately QM really only requires second order differentiability
of its objects, meaning that the proof never quite gets off the ground :(.

> Now if all this were to be the case, then maybe it says something very
> specific about the substrate on which consciousness runs.  There would
> be something special about the architecture which the substrate
> employs to implement consciousness because it relies on a certain mode
> of decay, facilitating the branching to a new born baby having an
> appropriate structure (portal?) to secure a consistent extension of
> the consciousness into  another branch.  Unless a computer could
> simulate such a special substrate then it could not be used to
> implement consciousness.  This would mean that it would be wise to say
> no to the Doctor! –  Comp might be false?
> The Turing principle (p135 of David Deutsch’s book – “the Fabric of
> Reality”) would imply that, a universal machine could simulate the
> physical structure of brains in such a way so as to be able to act as
> a medium whereby, if the above argument is possible, consistent
> extensions of conscious physical observers (persons) could avoid cul
> de sacs.  But until we can understand the nature of what consciousness
> is, we are stumped as to how a computer can be programmed to implement
> it.  However some alien civilizations may have known these techniques
> for ages now, thereby perhaps explaining why we each have lived even
> as long as we now perceive we have. A stronger statement would be that
> if universal virtual reality generators are physically possible, then
> they must be built somewhere in some universes!
> But supposing the above (reincarnational) speculation was false in
> some way.  In that case, I have yet to see a convincing argument as to
> how the the no cul de sac conjecture can be reconciled with people
> living  to great ages.  Whatever sampling assumption is applied, the
> facts are that we don’t typically see people reaching ages greater
> than 100+ yrs). Therefore either QTI is false or  people just don’t
> get old! Rather, the special physical conditions of death associated
> with dementia or oxygen starvation of the brain, facilitate continued
> extensions of consciousness by branching into worlds where we
> supervene over new born babies (or something – animals, aliens?) -
> accidental deaths of people of any “normal ages” we can think about
> could of course be accommodated by the NCDSC).

The observation that other people never seem to live beyond a certain
age is not evidence against the NCDSC. Only logical
impossibility can count. Even physical impossibility is insufficient,
because there is always the possibility of mind uploading into
machines that may be of arbitrary age.

Even Jacques Mallah accepted the possibility that people of
arbitrarily old age must exist somewhere in the Multiverse. What he
couldn't accept was the certainty of getting from here to there, that
the NCDSC implies. The refinement of that debate lead to the distinction of
ASSA vs RSSA, and the NCDSC.

> The mechanics of such  reincarnational transitions would be
> interesting to speculate about since I see this as the only way out
> for a QTI.
> Nick Prince

Thanks for giving this some more thought.

Prof Russell Standish                  Phone 0425 253119 (mobile)
UNSW SYDNEY 2052                         hpco...@hpcoders.com.au
Australia                                http://www.hpcoders.com.au

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